67 Impact of 12-lead ECG Wireless Transmission on Hospital STEMI Activations

Abstract

Study Objectives: We sought to evaluate the impact of wireless transmission of out-of-hospital field 12-lead electrocardiograms (ECGs) to hospital emergency departments (EDs) for potential ST elevation myocardial infarction (STEMI) patients. In particular, we focused on the impact of wireless field ECG transmission on emergent cardiac catheterization laboratory (cath lab) activation rates and times. Methods: We conducted a multicenter, before-after study at 3 area STEMI receiving hospitals (academic urban medical center, ED census of 40,000; community hospital, ED census of 27,000; and federal military hospital, ED census of 50,000) comparing STEMI measures during a 6-month period after implementation of community-wide ECG wireless transmission to hospitals from the out-of-hospital field (post-ECG), with a 6-month period prior to the ECG wireless implementation (pre-ECG). In the pre-ECG period, paramedics obtained field ECGs on all appropriate patients with complaint of chest pain or shortness of breath. Paramedics called for cath lab activation solely based on computer interpretation of the ECG. In the post-ECG period, the field ECG was transmitted wireless via 3-G cellular network and Internet to the hospital ED for viewing by ED and cardiology staff prior to patient arrival. The proportion of field cath lab activations and false-positive activations (activations for patients found not to require an immediate intervention) for all out-of-hospital patients with field ECGs were compared before and after ECG wireless implementation using a chi-square test and Fisher's Exact test, respectively. Median door-to-intervention time was compared using a Mann-Whitney U test. Results: During the pre-ECG period, there were 500 patients who had a field ECG obtained, of whom 40 cases resulted in a call to activate the cath lab for STEMI (8.0%). During the post-ECG period, there were 594 out-of-hospital patients who had a field ECG obtained, of which 12 cases resulted in activation of the cath lab after wireless ECG transmission (2.0%) (p<.001). The false positive activation rate was lower after wireless transmission was implemented, but was not statistically significant (25.0% in the pre-ECG period versus 16.7% in the post-ECG period; p=.708). Median door-to-intervention time was not significantly different between the pre- and post-ECG periods (57 versus 64 minutes, p=.122); however, 100% of all door-to-intervention times were less than 90 minutes during the post-ECG period, compared to 82% during the pre-ECG period. Conclusion: In this initial study at 3 cardiac receiving centers within a single region, wireless out-of-hospital ECG transmission resulted in fewer emergent cath lab activations from the field and fewer false-positive activations for non-STEMI patients with no change in door-to-intervention time.